North Korea’s cash-strapped government is offering to swap sand, resources licenses and rental income in return for concrete, steel and fuel, according to Munhwa Ilbo newspaper.

The government sent letters to companies in China and South Korea asking them to invest $320 million in a construction project in the capital, Pyongyang, the Korean-language paper reported. In addition to the investment, the government is seeking 30,000 tons of diesel and gasoline, 50,000 tons of steel bars and 300,000 tons of cement, the paper said, citing one of the letters.

In return, the letters offer investors long-term rental income, the rights to resource development and sand. North Korea’s finances are being squeezed by United Nations sanctions imposed because of the country’s nuclear weapons program.

The letters were sent to the companies via an investment group, the paper said. The government wants to build 100,000 homes in Pyongyang, it said.